306 



In farther evidence of this view he cites the difference in the anal spir- 

 acles of the esophageal or subcutaneous stage and the second stage of 

 the larva. In the former, as shown at Figs. A8d and 49c, these are 

 small, indicating a limited respiration, and in the latter (Fig. 49/) they 

 are much more prominent, indicating that as soon as the grub reaches 

 the air a larger respiratory apparatus becomes necessary. He argues 

 further from the nature of the food in the alimentary canal of the larvae 

 of the first and second stages as follows : 



The differences iu the food between the subcutaneous stage and the first cutaneous 

 stage, or certainly the second stage, is quite marked. Before the tunnel is made or 

 completed the contents of the alimentary canal are yellow, like the inflammatory 

 effusion it (the larva) excited, but after the sac forms, after it (the larva) loses the 

 mouth hooks iu the second stage, the contents become much darker, like the pus 

 secreted from the lining membrane of the sac. 



The different stages of the larvfe in the skin cysts can, he says, be 

 easily connected by dissecting out the whole cyst, and obtaining the 

 molted skin of the earlier stages. On reaching full growth the warble 

 forces its way out through the breathing hole, works into the ground, 

 and transforms to a perfect fly in from three to six weeks. Curtice's 

 specimens appeared after six weeks, Osborn's after four weeks, and one 

 bred by Mr. G. W. Hoi stein, of Albany, Texas, after about three weeks. 



As will be gathered from what has already been said in Insect Life, 

 I have heretofore taken Dr. Curtice's views with some caution, feeling, 

 however, that his facts justified his conclusions, and showed clearly 

 enough that at least a portion of the young bots are thus licked into 

 the mouth and pass to the back through the eso^ihagus and other tis- 

 sues, and the only question in my mind was whether this mode of de- 

 velopment was not exceptional and whether direct penetration into the 

 skin did not also occur. The first point, viz, that our Ox Bot is H. 

 lineata, having been confirmed and settled as indicated in the prelimin- 

 ary portion of this article, I have been for some time very anxious to 

 learn the actual facts in reference to oviposition, and have delayed pub- 

 lishing the present article, for which most of the illustrations have long 

 since been made, in order to obtain these additional facts. I am glad 

 to be able through the efforts of a reliable agent in Texas, who ijrefers 

 to remain anonymous, to present the facts of oviposition, and, as will 

 be seen, they fully confirm Dr. Curtice's views. They are also confirm- 

 atory of the fragmentary and in most cases unsul)stantiated accounts 

 of various observers, which I shall refer to later, and, it seems to me, 

 put at rest all question as to the habit of Hypoderma in this regard. 



A careful watch was maintained for the Heel Fly on the ranches 

 along the Pedernales River, and on January 29 of the present year a 

 single specimen of the fly was captured on the muddy banks of this 

 stream about 2 o'clock, at which time many head of cattle were stand- 

 ing in the middle of the shallow crossing. Further search for the flies 

 in the first days of February resulted in the discovery along the banks 

 of the stream, and in similar situations, of about one hundred, none 



